1. viewset介绍
DRF 允许将一组相关视图的逻辑组合到一个称为 ViewSet 的类中。
ViewSet 类只是一种基于类的 View，它不提供任何处理方法，如 .get() 或 .post()，而是提供诸如 .list() 和 .create() 之类的操作。
ViewSet 只在用 .as_view() 方法绑定到最终化视图时做一些相应操作。
通常，不是在 urlconf 中的视图集中明确注册视图，而是使用路由器类注册视图集，这会自动为您确定 urlconf。
1.1. 实例
继承ViewSet 后不需要在写 get() 方法
from rest_framework import viewsets
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from rest_framework import status
class BookViewSet(viewsets.ViewSet):
def list(self, request, *args, **kwargs):
queryset = models.Book.objects.filter(is_active=True)
ser = serializers.BookModelSerializer(instance=queryset, many=True)
return Response({'code': 1000, 'msg': 'ok', 'results': ser.data}, status=status.HTTP_200_OK)
def retrieve(self, request, *args, **kwargs):
queryset = models.Book.objects.filter(is_active=True)
book_obj = get_object_or_404(queryset, pk=kwargs.get("pk"))
ser = serializers.BookModelSerializer(instance=book_obj)
return Response({'code': 1000, 'msg': 'ok', 'results': ser.data}, status=status.HTTP_200_OK)
def create(self, request, *args, **kwargs):
ser = serializers.BookModelSerializer(data=request.data, many=False)
ser.is_valid(raise_exception=False)
obj = ser.save()
return Response({'code': 1000, 'msg': 'ok', 'results': serializers.BookModelSerializer(instance=obj).data},
status=status.HTTP_200_OK)
继续配置url.py , 在 as_view() 中指定 get/post/patch/put等方法对应的方法
re_path(r'^v3/book/$', views.BookViewSet.as_view({'get': 'list', 'post': 'create'})),
re_path(r'^v3/book/(?P<pk>.*)/$', views.BookViewSet.as_view({'get': 'retrieve'}))
2. ViewSetMixin
Viewset的基类，它重写了原来 django view 中 .as_view() 方法，使得注册Url变得更加简单，原生 Django View 通过重写 get 和 post 方法的具体视图来达到实现逻辑
在 Viewset 中则可通过:
view = MyViewSet.as_view({'get': 'list', 'post': 'create'})
在 ViewSetMixin类中 ，要求用户必须在url映射中指定 actions ，否则会抛出异常
class ViewSetMixin:
@classonlymethod
def as_view(cls, actions=None, **initkwargs):
cls.name = None
cls.description = None
cls.suffix = None
cls.detail = None
cls.basename = None
# 如果 actions 为None ， 会抛出异常提示
if not actions:
raise TypeError("The `actions` argument must be provided when "
"calling `.as_view()` on a ViewSet. For example "
"`.as_view({'get': 'list'})`")
for key in initkwargs:
if key in cls.http_method_names:
raise TypeError("You tried to pass in the %s method name as a "
"keyword argument to %s(). Don't do that."
% (key, cls.__name__))
if not hasattr(cls, key):
raise TypeError("%s() received an invalid keyword %r" % (
cls.__name__, key))
if 'name' in initkwargs and 'suffix' in initkwargs:
raise TypeError("%s() received both `name` and `suffix`, which are "
"mutually exclusive arguments." % (cls.__name__))
def view(request, *args, **kwargs):
self = cls(**initkwargs)
self.action_map = actions
for method, action in actions.items():
handler = getattr(self, action)
setattr(self, method, handler)
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
# And continue as usual
return self.dispatch(request, *args, **kwargs)
# take name and docstring from class
update_wrapper(view, cls, updated=())
# and possible attributes set by decorators
# like csrf_exempt from dispatch
update_wrapper(view, cls.dispatch, assigned=())
# We need to set these on the view function, so that breadcrumb
# generation can pick out these bits of information from a
# resolved URL.
view.cls = cls
view.initkwargs = initkwargs
view.actions = actions
return csrf_exempt(view)
def initialize_request(self, request, *args, **kwargs):
"""
Set the `.action` attribute on the view, depending on the request method.
"""
request = super().initialize_request(request, *args, **kwargs)
method = request.method.lower()
if method == 'options':
# This is a special case as we always provide handling for the
# options method in the base `View` class.
# Unlike the other explicitly defined actions, 'metadata' is implicit.
self.action = 'metadata'
else:
self.action = self.action_map.get(method)
return request
def reverse_action(self, url_name, *args, **kwargs):
"""
Reverse the action for the given `url_name`.
"""
url_name = '%s-%s' % (self.basename, url_name)
kwargs.setdefault('request', self.request)
return reverse(url_name, *args, **kwargs)
@classmethod
def get_extra_actions(cls):
"""
Get the methods that are marked as an extra ViewSet `@action`.
"""
return [method for _, method in getmembers(cls, _is_extra_action)]
def get_extra_action_url_map(self):
"""
Build a map of {names: urls} for the extra actions.
This method will noop if `detail` was not provided as a view initkwarg.
"""
action_urls = OrderedDict()
# exit early if `detail` has not been provided
if self.detail is None:
return action_urls
# filter for the relevant extra actions
actions = [
action for action in self.get_extra_actions()
if action.detail == self.detail
]
for action in actions:
try:
url_name = '%s-%s' % (self.basename, action.url_name)
url = reverse(url_name, self.args, self.kwargs, request=self.request)
view = self.__class__(**action.kwargs)
action_urls[view.get_view_name()] = url
except NoReverseMatch:
pass # URL requires additional arguments, ignore
return action_urls
viewset 中共包含 5 个类，其中 ViewSetMixin（） 为其他类的基类
2.1. viewsets 下面的视图类
2.1.1 ViewSet
class ViewSet(ViewSetMixin, views.APIView):
"""
The base ViewSet class does not provide any actions by default.
"""
pass
继承 ViewSetMixin, views.APIView 两个类，只需要在url中配置映射关系，在视图类中编写具体方法，如：1.1. 实例
2.1.2. GenericViewSet
class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
"""
The GenericViewSet class does not provide any actions by default,
but does include the base set of generic view behavior, such as
the `get_object` and `get_queryset` methods.
"""
pass
继承 ViewSetMixin, generics.GenericAPIView 两个类
使用如下:
class BookViewSetMixin(GenericViewSet):
serializer_class = serializers.BookModelSerializer
queryset = models.Book.objects.all()
def list(self, request, *args, **kwargs):
queryset = models.Book.objects.filter(is_active=True)
ser = serializers.BookModelSerializer(instance=queryset, many=True)
return Response({'code': 1000, 'msg': 'ok', 'results': ser.data}, status=status.HTTP_200_OK)
def create(self, request, *args, **kwargs):
ser = serializers.BookModelSerializer(data=request.data, many=False)
ser.is_valid(raise_exception=False)
obj = ser.save()
return Response({'code': 1000, 'msg': 'ok', 'results': serializers.BookModelSerializer(instance=obj).data},
status=status.HTTP_200_OK)
2.1.3. ReadOnlyModelViewSet
class ReadOnlyModelViewSet(mixins.RetrieveModelMixin,
mixins.ListModelMixin,
GenericViewSet):
"""
A viewset that provides default `list()` and `retrieve()` actions.
"""
pass
继承 mixins.RetrieveModelMixin,mixins.ListModelMixin,GenericViewSet 三个类，在使用中，可以不用写list()方法
实例:
from rest_framework.viewsets import ReadOnlyModelViewSet
class BookViewSetMixin(ReadOnlyModelViewSet):
serializer_class = serializers.BookModelSerializer
queryset = models.Book.objects.all()
def retrieve(self, request, *args, **kwargs):
queryset = models.Book.objects.filter(is_active=True)
book_obj = get_object_or_404(queryset, pk=kwargs.get("pk"))
ser = serializers.BookModelSerializer(instance=book_obj)
return Response({'code': 1000, 'msg': 'ok', 'results': ser.data}, status=status.HTTP_200_OK)
def create(self, request, *args, **kwargs):
ser = serializers.BookModelSerializer(data=request.data, many=False)
ser.is_valid(raise_exception=False)
obj = ser.save()
return Response({'code': 1000, 'msg': 'ok', 'results': serializers.BookModelSerializer(instance=obj).data},
status=status.HTTP_200_OK)
2.1.4. ModelViewSet
class ModelViewSet(mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
"""
A viewset that provides default `create()`, `retrieve()`, `update()`,
`partial_update()`, `destroy()` and `list()` actions.
"""
pass
继承ModelViewSet 类后，内部已经实现了 create(), retrieve(), update(),
partial_update(), destroy() and list() 这些方法，只需要 指定 serializer_class 和 queryset 字段就可以直接使用
实例：
from rest_framework.viewsets import ModelViewSet
class BookViewSetMixin(ModelViewSet):
serializer_class = serializers.BookModelSerializer
queryset = models.Book.objects.all()